Structural and magnetic properties of flame aerosol synthesized

  • Slides: 10
Download presentation
Structural and magnetic properties of flame aerosol synthesized nanoparticles Prakash Kumar, M. P. Dudukovic,

Structural and magnetic properties of flame aerosol synthesized nanoparticles Prakash Kumar, M. P. Dudukovic, Da-Ren Chen, Richard Axelbaum, Ronald Indeck, Pratim Biswas

Applications Recording devices • Magnetic tapes for audio and video recording • Floppy discs

Applications Recording devices • Magnetic tapes for audio and video recording • Floppy discs for computer data Environmental • Recovery of nanoparticles from the waste • Prevention scale formation in heat exchangers Biomedical • Biocompatible ferromagnetic particles for targeted drug delivery • Selective deposition of magnetic particles for Tumor necrosis • Magnetic particles guided by external magnetic field for Aneurysm treatment

Synthesis of Magnetic Nanoparticles n Experimental setup n Investigation of process parameters on physical

Synthesis of Magnetic Nanoparticles n Experimental setup n Investigation of process parameters on physical properties of synthesized maghemite particles ¨ ¨ ¨ n Temperature of flame Temperature gradient at collecting surface Precursor concentration Residence time in flame Sampling position Experimental results q q Morphology and phase composition Magnetic properties

Experimental Setup

Experimental Setup

Experimental Setup

Experimental Setup

Measurement Methods Measuring Instrument Physical properties Scanning electron microscopy, BET, TEM Particle size, shape,

Measurement Methods Measuring Instrument Physical properties Scanning electron microscopy, BET, TEM Particle size, shape, and distribution X-ray Diffraction Particle phase, lattice parameters, composition Vibrating sample magnetometry Hystersis curve, mangetization, coercivity Scanning mobility particle sizer Particle size distribution Thermocouple Flame temperature Operating conditions

Phase Composition, Crystallanity Crystalline Hematite Bragg’s Law Crystalline Maghemite Amorohous : Angle of reflection

Phase Composition, Crystallanity Crystalline Hematite Bragg’s Law Crystalline Maghemite Amorohous : Angle of reflection : Wavelength of X-ray d: lattice spacing n: order of diffraction peak

XRD pattern for maghemite samples after heat treatment (precursor: Iron pentacarbonyl) Maghemite ( Fe

XRD pattern for maghemite samples after heat treatment (precursor: Iron pentacarbonyl) Maghemite ( Fe 2 O 3) Hematite ( Fe 2 O 3)

Morphology and Magnetic Properties of Flame Synthesized Nanoparticles Maghemite ( Fe 2 O 3)

Morphology and Magnetic Properties of Flame Synthesized Nanoparticles Maghemite ( Fe 2 O 3)

Conclusions ü Particles are observed to be crystalline at a higher sampling height from

Conclusions ü Particles are observed to be crystalline at a higher sampling height from the nozzle of the burner compared to amorphous nature of particles collected at low sampling height. ü X-ray diffraction and VSM results of the powder collected show the presence of pure Fe 2 O 3 with high saturation magnetization. ü In the case of lower temperature in flame, particles with single crystal are synthesized having a high saturation magnetization and coercivity. ü In the case of high temperature in flame, particles are sphericalin shape, having low saturation magnetization and coercivity. ü Flame pyrolysis of Iron pentacarbonyl gives maghemite, of Ferrocene gives Magnetite; whereas Iron nitrate gives Hematite. ü Post heat treatment of maghemite and magnetite showed to gradually transform to hematite at 500 C.